<template>
  <div class="score-case">
    <div class="table">
      <table>
        <thead>
          <tr>
            <th>编号</th>
            <th>科目</th>
            <th>成绩</th>
            <th>考试时间</th>
            <th>操作</th>
          </tr>
        </thead>
        <tbody>
          <!-- 1.遍历数组 -->
          <tr v-for="(item,index) in list" :key='item.id'>
            <td>{{index+1}}</td>
            <td>{{item.subject}}</td>
            <!-- 2.动态添加属性 -->
            <td :class="item.score< 60 ? 'red' : '' ">{{item.score}}</td>
            <!-- 4.通过moment渲染时间 -->
            <td>{{dateFn(item.date)}}</td>
            <!-- 5.给删除绑定事件,通过id操作 -->
            <td><a href="#" @click='del(item.id)'>删除</a></td>
          </tr>
          <!-- <tr >
            <td>2</td>
            <td>数学</td>
            <td>100</td>
            <td>Tue Jun 07 2022 10:00:00 GMT+0800 (中国标准时间)</td>
            <td><a href="#">删除</a></td>
          </tr> -->
        </tbody>

        <!-- 8.v-show数组长度为0时显示 -->
        <tbody v-show="list.length===0">
          <tr>
            <td colspan="5">
              <span class="none">暂无数据</span>
            </td>
          </tr>
        </tbody>
        <!-- v-show数组有长度时出现 -->
        <tfoot v-show="list.length>0">
          <tr>
            <td colspan="5">
              <span>总分：{{totalScore}}</span>
              <span style="margin-left:50px">平均分：{{avgScore}}</span>
            </td>
          </tr>
        </tfoot>
      </table>
    </div>
    <div class="form">
      <div class="form-item">
        <div class="label">科目：</div>
        <div class="input">
          <!-- 6.v-model双向绑定  .trim去除左右空格-->
          <input type="text" placeholder="请输入科目" v-model.trim="subject"/>
        </div>
      </div>
      <div class="form-item">
        <div class="label">分数：</div>
        <div class="input">
          <!-- .number转化为数字 -->
          <input type="text" placeholder="请输入分数"  v-model.number="score"/>
        </div>
      </div>
      <div class="form-item">
        <div class="label"></div>
        <div class="input">
          <!-- 7.添加 -->
          <button class="submit" @click='add'>添加</button>
        </div>
      </div>
    </div>
  </div>
</template>

<script>
//3.引入moment
import moment from "moment"

export default {
  name: 'ScoreCase',

  data () {
    return {
      list: JSON.parse(localStorage.getItem('score-case'))||[],
      subject: '',
      score: ''
    }
  },

methods:{
  //时间
  dateFn(dt){
    return moment(dt).format('YYYY-MM-DD HH:mm:ss')
  },

  //删除,filter
  del(id){
   this.list= this.list.filter(item=>item.id !== id)
  },

  //添加,push对象进去
  add(){
    //校验判断
    if(this.score>=0 && this.score <=100 && this.subject){
      this.list.push({
      id:+new Date,
      subject:this.subject,
      score:this.score,
      date:new Date()
    })
    }else{
      alert('请输入正确信息')
    }
  }
},

computed:{
  //求和 reduce
  totalScore(){
  return this.list.reduce((sum,item)=>sum+item.score,0)
  },

  //平均数 判断数组是否有长度
  avgScore(){
    return this.list.length ? (this.totalScore/this.list.length).toFixed(2) : 0
  }
},

//深度监听
watch:{
  list:{
    deep:true,
    handler(){
       localStorage.setItem('score-case',JSON.stringify(this.list))
    }
    

  }
}



};
</script>

<style lang="less">
.score-case {
  width: 1000px;
  margin: 50px auto;
  display: flex;
  .table {
    flex: 4;
    table {
      width: 100%;
      border-spacing: 0;
      border-top: 1px solid #ccc;
      border-left: 1px solid #ccc;
      th {
        background: #f5f5f5;
      }
      tr:hover td {
        background: #f5f5f5;
      }
      td,
      th {
        border-bottom: 1px solid #ccc;
        border-right: 1px solid #ccc;
        text-align: center;
        padding: 10px;
        &.red {
          color: red;
        }
      }
    }
    .none {
      height: 100px;
      line-height: 100px;
      color: #999;
    }
  }
  .form {
    flex: 1;
    padding: 20px;
    .form-item {
      display: flex;
      margin-bottom: 20px;
      align-items: center;
    }
    .form-item .label {
      width: 60px;
      text-align: right;
      font-size: 14px;
    }
    .form-item .input {
      flex: 1;
    }
    .form-item input,
    .form-item select {
      appearance: none;
      outline: none;
      border: 1px solid #ccc;
      width: 200px;
      height: 40px;
      box-sizing: border-box;
      padding: 10px;
      color: #666;
    }
    .form-item input::placeholder {
      color: #666;
    }
    .form-item .cancel,
    .form-item .submit {
      appearance: none;
      outline: none;
      border: 1px solid #ccc;
      border-radius: 4px;
      padding: 4px 10px;
      margin-right: 10px;
      font-size: 12px;
      background: #ccc;
    }
    .form-item .submit {
      border-color: #069;
      background: #069;
      color: #fff;
    }
  }
}
</style>